I would recomend the east coast for all except the devils in the wild (not sure where you can see them in the wild). I would probably start in Hobart have a night or two at Frecineyt (where there is some great bush walking), see the penguins in Bicheno and then continue up the coast before flying out of Launceston. There are some good places to eat along the way which will have oysters and other seafood.